Lubricating composition



' of this invention relates to v slip differential,

purpose additives,

United States Patent Glendale,

This invention relates to certain new S-amine O,O-dialiphatic phosphorothioates and to improved lubricating compositions containing the same. A particular aspect the improvement of the lubrilubricating oils by the eating properties of hydrocarbon 0,0-dia1iphatic phosaddition thereto of certain S-amine phorothioates.

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2 specifications of MIL-L-210=5A, would not meet those specifications after the-addition of one of these known lubricity agents in an amount sufficient to eliminate the stick-slip problem. It is an object of this invention to provide a class of new compounds which, when combined with a hydrocarbon oil such as a mineral oil fraction of appropriate lubricating viscosity, are efiective to improve the anti- Wear and extreme-pressure lubricating characteristics of such oils. A further object is to provide improved lubrieating compositions which alleviate the stick-slip problem associated wtih limited-slip differentials and also eliminate the undesirable disturbance in automatic transmissions known as squawk which occurs when thebands of such a transmission are engaged. It is also an object of this invention to provide a class of compounds which,

' when combined with, certain other classes of oil addition The phosphorothioates contemplated by this invention generally improve the antiwear and extreme-pressure lubricating characteristics of the base oil. In addition, these phosphorothioates can be combined withcertain other addition agents which together cooperate with each other and the base oil to provide lubricating compositions having performance levels more than adequate to-meet the extreme requirements of vehicle differentials having both hypoid-type gears and limited-slip mechanisms.

Due to design, a conventional differential will always drive the wheel which offers the least resistance to turning. As a result, a vehicle equipped with a conventional differential, under adverse conditions, loses traction drivin g force as evidenced by wheel spinning when the traction wheels bounce over rough roads or non-uniform traction surface conditions such as ice and snow spots, wet and dry pavements, sand and gravel.

. There has recently been commercialized for use with passenger cars, station wagons, light trucks, and the like, a mechanism known as a locking diflerential or limitedwhich mechanism permits an automotive axle to transmit the major driving force to the Wheel, with the better traction thus minimizing the disadvantages of driving, under adverse conditions, a vehicle equipped with a conventional differential.

With the commercial advent of limited-slip differentials, the use of known hydrocarbon lubricating oils and hydrocarbon lubricating oil compositions containing additives therein has not proved adequate to meet the lubrication requirements of both the hypoid gears and the limitedslip differential mechanism. The non-effectiveness of said known oils and compositions is apparent in the case of a limited-slip differential, for example, from the stick-slip action (resulting in an objectionable chatter which may reach the proportion of thumping) resulting when a vehicle provided with such a device makes a turn, thus instigating action in the limited-slip mechanism.

Various known lubricity agents havebeen added to gear lubricants in attempts to alleviate the stick-slip problem. In general, while these lubricity agents, such as methyl oleate, glycerolmono-oleate, desulfurized degras'and sul- I furized sperm oil, help to alleviat'e'the stick-slip problem it was found that other properties which were built into the gear lubricants to meet the requirements of the hypoid .gearing were deleteriously affected. Thus, for example, a hydrocarbon oil lubricant containing various multiwhich lubricant would meet the agents, cooperate with each other and the base oil to provide hydrocarbon oil compositions which pass the MIL-L-ZlOSA'spettification and, in addition, satisfactorily alleviate the stick-slip problem of limited-slip dif-. ferential mechanisms. It is also an object of this invention to provide a class of compounds whichprovide a significant improvement in the antiwear properties of a hydrocarbon oil or hydrocarbonoil containing various additives when added thereto in relatively small amounts.

In its broadest aspect,vthe lubricating compositions of our invention comprise a major amount of a hydrocarbon oil, such as a mineral oil fraction of suitable lubricating viscosity, and a minor amount of certain S-amine 0,0 dialiphatic phosphorothioates of the formula formed by the reaction of amines of the formula In each of the Formulae I, II and III above, 111 is an integer from 0 to 17, n is an integer from 0 to 17, the sum of m and n being from 9'to 17, R is selected from CH=CH- and sulfurized CH=CH; R and R are selected from hydrogenand aliphatic radicals containing from 1 to' 4 carbon atoms; X is selected from oxygen and sulfur, butpreferably'sulfur; and R and R are each-aliphatic radicals containing from 1 to 12 carbon atoms, the sum of the carbon atoms of R and R being at least 3, but when the sum of m and n is 9, R and R each contain not more than 9 carbon atoms.

The aliphatic radicals from which R and R3 can be selected are preferably alkyl radicals containing from 1 m4 carbon atoms, but can be other aliphatic radicals,

such as hydroxypropyl, hydroxyethyl, beta-chloroethyl,

be selected are preferably alkyvl radicals, such as methyl, ethyl, propyl (nand iso-), butyl (n-, sec.-, isoand tert.-), amyl (n-, sec.-, isoand tert.-); hexyl radicals, such as nand sec.-2,2-dimethyl-3-butyl, 2,2-dimethyl-4- butyl, 2,3-dimethyl-2-butyl, Z-methyl-l-pentyl, Z-methyl- Z-pentyl, 3-methyl-1-pentyl, 3-rnethyl-2-penty-l; heptyl radicals, such as nand sec.-2,3dimethyl-pentyl, 2,4-dimethyl-Z-pentyl, 2,4-dimetl1yl 3 pentyl, 2,2,3-trimethyl- 3-butyl, 3-ethyl-2-pentyl, Z-methyl-Z-hexyl; octyl radicals, such as n-Z-ethylhexyl, diisobutyl, capryl; nonyl radicals, such as n-diisobutyl carbinyl; idecyl radicals, such as nand iso-decyl; undecyl radicals and dodecyl radicals; and especially those alkyl radicals derivable from the oxo process; halogen-containing alkyl radicals such as alkenyl radicals, such as vinyl; propenyl radicals, such as allyl and iso-propenyl; butenyl radicals, such as n-butenyl-l, n-butenyl-Z, n-butenyl-3, iso-butenyl; pentenyl radicals, such as n-pentenyl-l, n-pentenyl-Z, n-pentenyl-3; hexenyl radicals, such as n-hexenyl-l, n-hexenyl-Z, n-hexenyl-3, 4,4-dimethylbutenyl-2, 3,4 dimethylbutenyl 1; heptenyl radicals, such as n-heptenylgoctenyl radicals, such as noctenyl, diisobutenyl; nonenyl radicals, such as n-nonenyl; decenyl radicals, such as n-decenyl, iso-decenyl, undecenyl; dodecenyl radicals, such as n-dodecenyl and triisobutenyl; cycloalkyl nadicals, such as cyclopentyl, alkylated cyclopentyl; cyclohexyl and alkylated cyclohexyl radicals, such as monoand polymethyl cyclopentyl, monoand polymethyl cyclohexyl, monoand polyethyl cyclohexyl, monoand polyisopropyl cyclohexyl, and mono-tert.amyl cyclohexyl; cycloalkenyl radicals, such as cyclopentenyl, alkylated cyclopentenyl, cyclohexenyl, alkylated cyclohexenyl; cycloalkyl-substituted alkyl radicals, such as cyclopentylethyl, cyclohexylethyl, methylcyclohexylethyl; alkoxy-substituted alkyl radicals; cycloalkoxy-substituted alkyl radicals; alkenoxy-substituted alkyl radicals; alkoxy radicals;

and cycloalkyl radicals containing sulfur. Preferably, R and R are selected from normal and branched chain alkyl radicals containing 3 to 6 carbon atoms.

Examples of amines which can be used in our invention are dodecylamine, dodeceny-lamine, sulfurized dodecenylamine, tridecylamine, tridecenylamine, sulfurized tridecenylamine, tetradecylamine, N,N-2-hydroxypropyl octadecenyl amine, N,N,N di 4 2 hydroxypropyl octadecenylamine, N,N-hydroxyethyl octadecenylamine, N, N-hydroxybutyl octadecenylamine, tetradecenylamine, sulfurized tetradecyenylamine, pentadecylamine, pentadecenylamine, sulfurized pentadecyenylamine, hexadecylamine, henadecenylamine, sulfurized hexadecyenylamine, heptadecylamine, heptadecenylamine, sulfurized heptadecyenylamine, octadecylamine, octadecenylamine, sulfurized octadecyenylamine, nondecylamine, nondecenylamine, sulfurized nondecyenylamine, eicosylamine, eicosylnylamine, sulfurized eicosyenylamine, methyldodecylamine, dimethyldodecylamine, .diisopropyl pentadecylene amine, diethyl octadecenylamine, methylethyl octadecylamine, methylbutyl sulfurized octadecyenylamine and 'dimethyl eicosylamine. By sulfurized, as used herein (for example, sulfurize ddodecenylamine), we mean that sulfur has been introduced into an olefinic bond, although the precise chemical structure of the resulting product is uncertain. The sulfurization of the compounds disclosed herein can be accomplished by methods known to the art.

The compounds of Formula I can be prepared by methodsknown to the art. As non-limiting examples of the preparation of such compounds, the following are illustrative. Parts are parts by weight unless otherwise stated.

4 EXAMPLE 1 Into a clean, dry, suitable reaction vessel, having means for agitating, cooling and heating the contents thereof, there were charged 287 parts of oleylamine. While agitating and cooling, 318 par-ts of di(1,3-dimethylbutyl) phosphorodithioic acid were slowly added to the amine in the reactor. Reaction between the amine and the acid was almost instantaneous and Was accompanied by the evolution of heat. The temperature of the vessel contents was maintained at 45 C. throughout the reaction period. After all of the acid had been added, agitation was continued for about 30 minutes, after which time a small additional portion of acid was added in order to obtain'an essentially neutral mass. The resultant product, S-oleylamine 0,0-di(1,3-dimethylbutyl) phosphorodithioate, was a dark amber liquid having a viscosity of about 314.69 centistokes at 100 C. and 24.96 centistokes at 210 C., anda specific gravity at 60/ 60 of 0.0934.

EXAMPLE 2 Utilizing the equipment of Example 1, there were charged 280 parts of a technical grade stearylamine containing essentially 93% saturated C 1% unsaturated C and 6% saturated C primary amines. Three hundred parts of di(1,3-dimethylbutyl) phosphorodithioic acid were slowly added to the amines Without cooling. After addition of the reactants was employed, the mixture was heated to about 60 C. to effect .final solution of the materials in the vessel; Thereafter a small amount of acid was added in order to provide a neutral material. The resultant product, essentially S-stearylamine 0,0-di- (1,3-dimethylbutyl) phosphorodithioate, was a fluid, viscous mass.

EXAMPLE 3 Utilizing the equipment of Example 1, 244 parts of isopropyl alcohol were added to the reaction vessel, to which were then slowly added 222 parts of P 8 while maintaining the temperature of the reactants at about 60 C. After completing the P 8 addition, the reaction product, di-isoprcpyl phosphorodithioic acid, was filtered and then held under vacuum for about two hours to remove'residual H 8.

Thereafter 78 parts of the above prepared acid and parts of oleylamine were reacted at about 60-70 C. An additional small quantity of said acid was added to adjust the pH to about 6.5-7.0 and the desired product, S-octadecenylamine 0,0-djisopropyl phosphorodithioate, was recovered.

As herein-before stated, the amine portion of the additives of our invention can be saturated, unsaturated or sulfurized. Saturated amines are available commercially, but can also be prepared by hydrogenation of unsaturated amines by methods known to the art, as, for example, by hydrogenation using a nickel catalyst. Sulfurized amines can be prepared from unsaturated amines by known methods, such as, for example, by the slow addition of sulfur to unsaturated amines at a temperature of about C.

The additives of the present invention can be employed in any hydrocarbon oil or hydrocarbon oil composition. Thus, for example, our additives can be employed in ordinary oil-base lubricants, as Well as the so-called heavy-duty types of lubricants containing various functional additives. Suitable base stocks include, for example, mineral oils and synthetic oils. An example of a mineral oil is a petroleum fraction of lubricating viscosity. Examples of synthetic oils are those obtained by the polymerization of olefins, cracking coal tar fractions, animal, vegetable or fish oils or their hydrogenated products, and mixtures thereof with mineral oils. The viscosity of the oil may vary, depending upon the intended application of the finished lubricant, from about 1 to about 10,000 centistokes at 100 F. Particularly preferred for use in this invention, i.e., in the hypoid gears of automotive vehicles, are hydrocarbon oils having viscosities from aboutdO to about 1500 centistokes at 100 F. The oil should, of course, also be selected on the basis of, suitable pour point and viscosity index characteristics for the specific purpose intended, it being understood that the desired characteristics of the finished lubricant may be obtained by the addition of lubricating oil additives to been replaced with a thiocarbonate group. Suitable ali-' phatic materials in either case are those containing from 5 to about 24 carbon atoms.

When a chlorinated aliphatic material is to be used, the higher carbon content materials are preferred, especially petroleum wax or similar material, and chlorination is carried to the level where the average amount'of chlorine substituted is about 30% tov70% of the theoretical maximum, and preferably to about 40% to 50% of the theoretical maximum in order to obtain maximum benefit of such an additive without a serious decrease in slubil-' ity, which normally occurs when a highly chlorinated material is used.

When a chlorinated aliphatic material-thiocarbonate reaction product is used, it is usually preferable to use aliphatic materials having from about to about carbon atoms, since the extremely short-chain and extremely long-chain materials are more difficult to react and are less eflicient in their effect upon the final formulation. Preferably, a kerosene containing about an average of 10 carbon atoms and having a boiling range of from about 150 C. to about 275 C. is used.

The thiocarbonate group which is used to replace a part of the chlorine is derived from an alkali (Na, K, Li) or alkaline earth (Ca, Sr, Ba) metal salt of a thiocarbonic acid, preferably an alkyl thiocarbonic acid. The thiocarbonate radical may be a mono-, dior trithiocarbonate, but, in general, preference is given to the dithiocarbonate (xanthate) compounds, characterized by the divalent group (008 The trithiocarbonate type of compounds, characterized by the divalent group (CS have also been prepared and have been found to form effective extremepressure agents in combination with the chlorinated aliphatic material, but from the standpoint of odor and cost, we prefer products in which the thiocarbonate constituent is a xanthate group.

A procedure which may be followed in synthesizing this material involves substantial chlorination of an aliphatic compound or a predominantly aliphatic material, such as a petroleum naphtha, followed by reaction of the chlorinated material with an alkali or alkaline earth metal salt of an alkyl thiocarbonic acid in such proportions and nude such conditions that only part of the chlorine is replaced by the alkyl thiocarbonate.

As to the 'substituents in the thiocarbonate or xanthate groups which are substituted in the chlorinated aliphatic material, it is preferable that such substituents be derived from aliphatic compounds of relatively low molecular weight, e.g., methyl, ethyl, propyl and butyl. There is no particular advantage to be gained by having a long-chain alkyl group in the xanthate or thiocarbonate substituent from the standpoint of solubility, etc, and the lower molecular weight alkyl groups give a finished product in which the content of the chlorine and characterizing divalent thiocarbonate groups (O CS, OCS or CS is somewhat more highly concentrated.

Examples of the thiocarbonate or xanthate materials which may be reacted with chlorinated aliphatic materials to provide extreme-pressure agents of the type discussed are sodium or potassium methyl, ethyl, propyl, isopropyl, butyl, .amyl, hexyl, octyl, decyl or dodecyl xanthates or the corresponding monoor trithiocarbonates.

It is desired that the proportions of reactants used and the conditions of reaction be controlled so that the final product contains bothchlorine and'thiocarbonate characterizing groups in chemical combination with the aliphatic hydrocarbon material. The relative amounts of chlorine and sulfur, or, more specifically, of chlorine and thiocarbonate characterizing groups, .in the finished product may be varied over a relatively wide range, but, in general, .itmay be said that the finished product should preferably be one which contains from about 25% to 40% of chlorine and'from'about 7% to 15% of sulfur. Expressing the sulfur content as the equivalent amount of characterizing thiocarbonate groups-present in the product, such preferred products are more accurately identified as containing from about 10% to about 22% characterizing dithiocarbonate or xanthate (divalent OCS groups or from about 7% to about 17% characterizing trithiocarbonate (divalentCS- groups. For general purposes, it may be said that the characterizing thiocarbonate group content is preferably from about 7% to about 22%.

A Specific non-limiting example of the preparation of a chlorinated aliphatic-thiocarbonate reaction product is given below. Parts are in parts by weight.

, EXAMPLE A A chlorinated naphtha is first prepared by chlorinating petroleum naphtha (Stoddard solvent) until it contains about 54% by Weight of chlorine. Two hundred parts of the chlornaphtha are then dissolved in about 500 parts of acetone and placed in a reaction vessel heated by a water jacket and equipped with stirrer and reflux condenser. To this solution, parts of potassium isopropyl xanthate are added and the mixture held at its boiling temperature with stirring under refiux for about 2 hours. The resulting mixture is cooled to room temperature, filtered, and the filtrate subjected to distillation to remove the acetone. After removal of the acetone, the product is washed to remove potassium salts and is dried and filtered. The finished reaction product obtained by the foregoing procedure is a dark'brown liquid containing about 11% sulfur, or, more specifically, about 16% of the characterizing xanthate (divalent OCS group, and 34% chlorine.

Variation in xanthate and chlorine content of the reaction product can be obtained by varying the degree of chlorination of the naphtha, by varying the amount of .alkali xanthate used, and by varying the hydrocarbon substituent in the alkali xanthate. Thus, products of widely varying chlorine and xanthate content are readily possible.

.Type B.A metal salt of a dithio acid ofphosphorous represented by the structure,

v /P\ Ill 112(0): S n

where R andR v are like or unlike and are selected from acyclic, alicyclic, aromatic and substituted aromatic radicals, M is a metal selected from Zn, Ba, Mg and Ca, but preferably Zn, n is the valence of M, and x is 1 (phosphoric acids) or 0 (phosphinic acids). Examples of acyclic radicals are propyl, butyl, isobutyl,

amylcyclo- A non-limiting example of the preparation of a metal salt of a dithio acid of phosphorus is the following:

EXAMPLE B To a suitable reaction vessel are added and intimately mixed approximately 4 molecular proportions of methyl isobutyl carbinol and approximately one molecular proportion of phosphorus pentasulfide. The mixture is heated at 90-100 C. for about three hours employing a pressure slightly below atmospheric. Thereafter the reaction product (a dithiophosphoric acid) is decanted from the unreacted phosphorus pentasulfide and admixed with a small amount of water and zinc oxide in excess of that theoretically required. The mixture is heated at about 60 C. for about three hours, cooled and filtered. The dark oily zinc salt of di(l,3-dimethylbutyl) dithiophosphoric acid so obtained analyzes approximately, in weight ratio, one part of phosphorus and approximately 2.2 parts of sulfur per one part of zinc.

Type C.-A phosphorized-sulfurized dicyclic terpene obtained by reacting a dicyclic terpene, such as carene, pinene, camphene,'fenchene and similar terpenes containing one double bond in the molecule and comprising tworing systems, with a phosphorus sulfide at a temperature of about 100l60 C. While any phosphorus sulfide, such as P285, P386, P486, P483, P487, etc., can be employed in the preparation of said reaction products, the preferred reaction products arethose obtained employing phosphorus pentasulfide (P 8 While the proportions of these reactants will vary depending upon the oil-solubility and oil-improvement properties desired, the preferred product is that obtained by the reaction of about one mol of a phosphorus sulfide with about four mols of a dicyclic terpene at a reaction temperature in the range of about 100160 C.

As a non-limiting example of the preparation of an oihsoluble sulfurizedand phosphorized-dicyclic terpene, the following is illustrative. Parts are parts by weight.

EXAMPLE C A mixture of 245 parts of pinene (substantially 1.8 mol) and 220.5 par-ts of mineral oil (SAE-lO) grade motor oil) is charged into a suitable reaction vessel and is heated to 11011 5 C. While stirring, 100 parts of phosphorus pentasulfide (substantially 0.45 mol) are added slowly while maintaining the temperature at 110-120 C. The temperature of the mixture is then increased to about 150 C. and stirred at that temperature for one hour. After partial cooling of the reaction mixture, there is added a small amount of clay and the mixture filtered.

The filtered product is a clear red viscous oil having a specific gravity of 1.02 at 15.6/15.6 C., a Saybolt viscosity of 145 at 210 F., analyzing about 4.7% phosphorus and about 13% sulfur and containing 43% by weight mineral oil. 7

Due to the sludge-forming characteristics of the phosphorized-sulfurized dicyclic terpene while in storage, it may be desirable to incorporate in the composition of this invention a small amount (e.g., 2% to by weight based onthe weight of the phosphorized-sulfurized dicyclic terpene) of an oil-soluble alkali metal or alkaline earth metal hydrocarbon sulfonate such as sodium, barium or calcium wax-alkylated benzene sulfonates or petroleum sulf-onates.

In general, in the preferred lubricating compositions of this invention, the weight ratio of the zinc dihydrocarbon 'dithiophosphate to the phosphorizedand sulfurized-dicyclic terpene will be approximately 1 to 9 parts of the former to 1 part of the latter, and the weight ratio of the chlorinated aliphatic material to the zinc dihydrocarbon dithiophosphate is approximately 0.5 to 3 parts of the former to 1 part of the latter, and the total weight percent based on the mineral oil base is in the range of about 4% to 20%. Optimum results, however, are obtained when the weight ratio of the zinc dihydrocarbon dithiophosphate to the phosphorized-sulfurized dicyclic rterpene is about 4 to 6.5 parts of the former to 1 part of the latter and wherein the weight ratio of the chlorinated aliphatic material, in which part of the chlorine has been replaced with a thiocarbonate group, to the zinc dihydrocarbon dithiophosphate is approximately 1 to 1.5 parts of the former to 1 part of the latter. Generally, we employ the aforedescribed three components so that their total weight is in the range of about 8% to 15% by weight based on the hydrocarbon oil.

In order to demonstrate the effectiveness of the compounds described above in fulfilling the objects hereinbefore stated, the following tests were utilized:

Shell Four-Ball Test Scar Composition Seizure width,

SAE Base Yes- 2.3 SAE 90 Base plus S-octadecenylamine 0,0- No 0.50

diethyl phosphorodithioate. SAE 90 Baseplus S-octadecenylamin 0,0- No 0.375

diisopropylphosphorodithioate. SAE 90 Base plus S-octndecenylamine 0,0- No 0.27

di(1,3-dimethy1butyl) phosphorodlthioate. SAE 90 Base plus S-octadecenylamine 0,0- No 0.375

dioctyl phosphorodithioate. SAE 90 Base plus S-octaclecenyl 0,0-didodecyl No 0.875

phosphorodithioate. SAE 90 Base plus S-dodeeylamine 0,0-di(1,3- No 0.425

dimethylbutyl) phosphorodithioate. 1 AE 90 Base plus S-dodecylamine 0,0-dioctyl No 0.575

phosphorodithioate. SAE 90 Base plus S-dodecylamine 0,0-didecy1 Yes- 0.675

phosphorodithioate (some insolubility). SAE 90 Base plus S-dodecyl 0,0-did0decyl phos- Yes- 0.075

phorodlthioate (some insolubility).

1 After 8 min.

oil, and that compounds outside the range of limits described for the additives of our invention do not possess the ability to impart these improved lubricant properties. H igh-Speed Axle Test This test is a research technique for determining loadcarrying and extreme-pressure lubrication characteristics of universal gear lubricants in axles under conditions of high speed and shock loading. All tests were performed according to the procedure established by the Coordinating Research Committee (CRC) and given the designation L-42458. This test differs from CRC test L19645' in that the peak torques are approximately two to three times those obtained in the L-19 procedure. Results of the L-42 test are stated as pass or fail, a pass being equivalent to the performancewhich is obtained with CRC Reference Gear Oil (R60')-11057.

High-Torque Axle T est This test is a research technique for determining loadcarrying, antiwear' and extreme-pressure lubrication propties of universal gear lubricants in axles under conditions or" high speed low-torque and low-speed high-torque using a single gear set. All tests were performed according to the procedure established by the CRC and given the designation L37-95'6, usually "known as L-37. This test differs from CRC L-20-545 in that there is high speed 'are arranged for the milder setting L-20. In the L-37 test, results are normally stated as pass, borderline (BL) and fail.

Limited-Slip Test This is a test devised to enable evaluation of the effectiveness of various additives in hydrocarbon oils in al-- leviating the stick-slip problem. The test is as follows: The apparatus to be used is assembled as required for a high speed and shock-loading test (CRC designation L42). In our tests we used a Spicer Model 44-1 rear axle equipped With gears having a 47:12 ratio (as required for the L-42 test), which had incorporated therein a limited-slip or looking differential device manufactured by the Dana Corporation. The clutch plates in the differential (which are part of the slip-limiting mechanism) (i.e., two splined plates between two tonged plates, giving three friction surfaces). The field current on the rightdynamometer (i.e.' the dyn-amometer occupying the position of the right rear wheel if the test equipment were a vehicle) is adjusted to give a 65-pound load at 100 r.p.m., and the field current on the left dynamorneter is adjusted to give a 15-pound load at 100 rpm. The carburetor idle screw is adjusted to give a 30-wheel rpm. at no load (i.e., no differentialin-g). After completing the above, maximum axle dif feren'tialing is obtained, using second gear of a four-speed transmission, by accelerating to IOO-Wheel r.p.m. using a 10-inch manifold vacuum. Differentialing and noises due to the action of the clutches are observed. The above cycle is repeated once using a 10-inch manifold vacuum and twice using a -inch manifold vacuum. The complete evaluation of the additive undergoing test is accomplished using the following dynamometer load combinations:

'nificance of the ratings is as follows:

Right Left The test composition is given a two-number rating, which rating is dependent upon the load conditions at which the first reproducible noise is observed. Thus, if under right or chatter) occurred at 265-15, and under left turn conditions, at 15-1 65, the additive would be rated 3-2.

If no noise is observed under any ofthe test conditions,

an additive would be rated 5--5. The temperature of the hydrocarbon oil composition within the "axle is maintained between 150 C. and 200 C. As a precautionary measure, a break-in and warm-up period for each composition is provided by running at speeds not' greater than 100- wheel r.p-.m., under conditions resultingin differentiating, first in one direction and then in the other. For a more stringent test, the clutch plates are arranged to provide live friction surfaces (i.e., by alternating the splined and tongued plates). In expressing the results, the average of a rating is usually expressed. Thus, a S-3 rating (or a 44 rating) would be expressed as a 4 rating. The sigof the test con- 5-Pass No chatter under any ditions.

4Pass Some chatter under severe test conditions.

3Borderline Chatter under severe test conditions.

2 or 1--Fail Chatter under mild test conditions.

The results observed in thela tter three tests are tabulated below. The percent additive .is percentby weight based on the weight of the hydrocarbon oil. I i

Test composition Limited-slip test Weight percent of additive L-42 L-37 Three friction surfaces Five friction surfaces Gear Oil "A.

phorodithioate.

phosphorodithioate. A plus S-octadeceny phosphorodithioate phosphorodithioate.

phosphorodithioate phosphorodithioate.

phosphorodithioate. A plus phorodithioate.

phorodithioate.

dithioate Gear dimethylbutyl phospho A plus S-stearylarnine A plus S-octadecenylamine 0,0-diethylphos- A plus S-octadecenylamine 0,0-di-2-chlorod iiilis fiti iiiifilin lamine 0,0-di-n-propyl A plus s-octadecenylainine 0,0-di-sec.-butyl A plus S-octadecenylamine- 0,0-di-isobutyl A plus s-octadecenylamine 0,0-di-sec.-amy1 methylbutyl phosphoro dithioate.

A plus S-octadecenyl 9,10-episulfide amine 0,0-di-1,3-dimcthylbutyl phospho'rodithioate. A plus S-octadecenyl A plus S-o'ctadeeenylamine O ,O-di-1,3-diamine 0,0-didodecyl S-dimethylstearylamine O O-di-1,3-

rodithioate. 0,0-diisopropyl phos- "A plus S-stearylamine O, 0-di-1,3-dimethylbutyl phosphorodithio A plus S-Arrneen HT butyl pho'sphorodithioate. A plus S-dodecylamine ate 1 0,0-di-1,3-di.methy1- Gear Oil B plus S-octadecenylamine 0,0-di- 1,3-dimethylbutyl phosphorodithioate.

Oil C plus S-octadecenylamine 0,0-di- 1,3-dimethylbutyl phosphorodithioate.

e 0,0-diisopropyl 0,0-didodecyl phos- A plus S-dodecylamine 0,0-di-1,3-dimethylbutylphosphorodithioate. A plus S-(N,N-2-hydr0xypropyl octadecenyl) amine 0,0-di-LB-dimethylbutyl phosphoro- 1 Pass.. Pass.

Pass.

Pass.

BL. Pass.

1 Arrneen HT, a product of Armour and Company, contains, by weight, 25% saturated Cm, saturated On, and 5% unsaturated Cia primary amines.

turn conditions a reproducible'noise (as a grindv The following table presents the results observed from using S-amine O,-O-dialiphatic phosphorothioates not within the aforedescribed class of suitable compounds:

which will give a performance capable of passing the L-37 and L-42 tests, can be used for applications where only a performance level as defined by the L-19-645 and Limited-slip test Weight Spl. Test composition percent L-42 L-37 No. of addi- Three Five tive friction friction surfaces surfaces 2l A plus S-octadecenylamine 0,0-dimethyl 0.125 v 2 Fail BL.

phosphorodithioate. 0.50 do Pass. 22 A plus S-octylamine 0,0-di-1,3-dimethyl- 0.35 3

butyl phosphorodithioate. 23.--" Aplus S-isoamylaniline 0,0-di-1,3-dirnethyl- 0.35 2

butyl phosphorodithioate. 24 A plus S-diethylamine 0,0-o1eyl, t-butyl 0.35 2

phosphorodithioate. 25.--" A plus S-methylamine 0,0-dio1eyl phos- 0.25 2

phorodithioate. 26-.- Aplus S-Primene .IMT 0,0-diisopropyl 0.35 2 phosphorodithioate. 0. 50 2 1 Primene JIM'l, a product of Robin and Haas, is a mixture of 018-024 highly branched primary amines.

The amount of the new additives of our invention used with a hydrocarbon oil or hydrocarbon oil composition can vary over a range dependent to some extent upon the particular application in which said oil is to be used. Generally, not over about by Weight is suflicient. When these additives are used in combination with additives in a hydrocarbon oil designed to give performance sufficient to pass the L49, L20, L-3'7 and L-42 tests,

the amount which is used will generally be from about 0.1% to about 1.5% by Weight, based upon the amount of said oil, although we prefer to use from about 0.25%

to about 1% by weight, based upon the oil content.

As is seen from the above results, the base composition (Gear Oil A) used would pass the L42 and L-37 tests, but would not pass the LSD test (sample 1). Gear Oils A, B and C contained the aforedescribed preferred additives in quantities falling within the specified ranges for such additives and, more particularly, had the following composition:

GEAR OIL A Ingredient: Percent by weight of composition Solvent-refined Mid Continent SAE 90 oil 90.1 Reaction product of :ExamplcA 4.3 Reaction product of Example B 4.3 Reaction product of Example C 1.3

Total 100.0

GEAR OIL B Ingredient: Percent by weight of composition Solvent-refined Mid-Continent SAE 90 oil 85.8 Reaction product of Example A 6.2 Reaction product of Example B 6.2 Reaction product of Example C 1.8

Total 100.0

GEAR OIL "0 Ingredient: Percent by weight of composition Solvent-refined Mid-Continent SAE 90 oil 86.0 Reaction product of Example A 6.1 Reaction product of Example B 6.1 Reaction product of Example C 1.8

Total 100.0

The additives used to make the base oil composition can be varied within the prescribed limits for those additives while maintaining performance levels adequate to pass the L-37 and L-42 tests. However, for purposes of showing the performance results of the additives of our invention, the base oil composition was not varied.

In addition to the aforedescribed, the additives of our invention are suitable for use in hydrocarbon oils of lubricating viscosity which, although not built to a level L20-545 tests is needed. Examples of such compositions are those containing about 2% to about 15% by weight of those preferred additives designated as type A and about 1% to about 5% by Weight of those preferred additives designated as type B. Such compositions can also contain a small amount of an oil-soluble alkali metal or alkaline earth metal hydrocarbon sulfonate as previously described. More particular examples of such compositons which also contain an additive of our invention are as follows. Percentages are by weight, based upon the hydrocarbon oil content. (D) SAE 90 Oil plus-- 7.5% chlorinated wax (about chlorination) 2.5% zinc dialkyl dithiophosphate .35% S-octadecenylamine 0,0-di-1,3-dimethylbutyl phosphorodithioate (E) SAE 90 oil plus 5.0% reaction product of chlorinated kerosene (containing about 10 carbon atoms) and sodium ethyl xanthate 4.2% zinc dihexyl dithiophosphate .35% S-octadecenylamine 0,0-di-1,3-dirnethylbutyl phosphorodithioate As stated above, the portion of the molecule of the additives of our invention, which is derived from dialiphatic phosphorothioates of Formula III, above, may be a preference for the latter. This preference is due to the fact that the presence of the oxygen markedly decreases the solubility of the additives. It should be noted that in either case the linkage.

Since the aliphatic radicals of the phosphorothioate portion of the molecule of the compounds of our invention (i.e., R and R can be the same or diflerent, it is intended to include the isomeric mixtures of diesters and mixed esters which are obtained in some cases by the methods used to prepare such compounds. Thus, for example, to prepare an aliphatic phosphorothioate in which the aliphatic groups are ethyl and butyl, P 8 can be reacted with a mixture of ethyl and butyl alcohols to yield a mixture of diethyl, dibutyl and ethyl, butyl phosphorothioates. We contemplate using such a mixture without separation of the isomers or using any of the specific isomers or combination of insomers. This application is a division of copending application Serial Number 751,902, filed July 30, 1958 (now Patent Number 3,002,014). I

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

.1. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, in an amount sufficient to improve the antiwear and extreme pressure properties of said oil but not over about 10% byweight, an S-amine 0,0-dialiphatic phosporothioate having the structure,

wherein m is an integer from to 17, n is an integer from 0 to 17, the sum of m and n is from 9 to 17; R is selected from the group consisting of -CH --CH sulfunized CH=CH-- and CH=CH- R and R are selected from the group consisting of hydrogen and aliphatic radicals containing from 1 to 4 carbon atoms; X is selected from the group consistingof oxygen and sulfur, and R and R are aliphatic radicals containing from 1 to 12 carbon atoms, the sum of the carbon atoms of R and R being at least 3, but when the sum of m and n is 9, R and R each contain not more than 9 carbon atoms. i

2. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, in an amount sufficient to improve the antiwear and extreme pressure properties of said oil but not over about 10% by weight, an S-amine 0,0-dialiphatic phosphorothioate having the structure,

wherein m is an integer from 0 to 17, rt is an integer from 0 017, the sum of m and n is from 9 to 17; R is selected from the group consisting of CH -CH sulfurized CH=CH and -CH=CH-; R and R are selected from the group consisting of hydrogen and aliphatic radicals containing from 1 to 4 carbon atoms; X is selected from the group consisting of oxygen and sulfur; and R and R are aliphatic radicals each containing from 3 to 6 carbon atoms.

3. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, in an amount suflicient to improve the antiwear and extreme pressure properties of said oil but not over about 10% by weight, an S-octadecenylamine 0,0-dialiphatic phos phorothioate having the structure,

wherein m is 7, n is 8, X is selected from the group consisting of oxygen and sulfur, and R and R are aliphatic radicals containing from 1 to 12 carbon atoms and the sum of the carbon atoms of R and R is at least 3.

4. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, in an amount sufiicient to improve the antiwear and extreme pressure properties of said oil but not over about 10% 14 by weight, an S-octadecenylamine, 0,0-dialiphatic phosphorodithioate having the structure,

wherein m is 7, n is 8, and R and R are alkyl radicals each containing from 3 to 6 carbon atoms.

5. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, in an amount sufficient to improve the antiwear and extreme pressure properties of said oil but not over about 10% by weight, an S-octadecenylamine 0,0-diisopropyl phosphorodithioate. I

6. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, in an amount sufficient to improve the antiwear and extreme pressure properties of said oil but not over about 10% by weight, an s-octadeceny-lamine 0,0-di-1,3-dimethy1- butyl phosphorodithioate.

7. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, based on said oil, about 2% to about 15% by weight of a chlorinated aliphatic material having from 5 to about 24 carbon atoms selected from the group consisting of chlorinated aliphatic hydrocarbons wherein the amount of chlotime is from about 30% to about 70% of the theoretical and the product obtained by chemically substituting a part only of the chlorine in a chor'inated aliphatic hydrocarbon with an alkyl thiocarbonate group, about 1% to about 5% by weight of a metal salt of a dithioacid of phosphorous of the structure,

Where R and R are selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals, M is a metal selected from the group consisting of Zn, Ba, Mg and Ca, n is the valence of M, and x is an integer from 0 to 1, and about 0.1% to about 1% by weight of an S-arnine 0,0-dialiphatic phosphorothioate of the structure wherein m is an integer from 0 to 17, n is an integer from 0 to 17, the sum of m and n being from 9 to 17; R is selected from the group consisting of sulfurized CH=CH- and -CH=CH-'-; R and R are selected from the group consisting of hydrogen and aliphatic radicals containing from 1 to 4 carbon atoms; X is selected from the group consisting of oxygen and sulfur; and R and R are each aliphatic radicals containing from 1 to 12 carbon atoms, the sum of the carbon atoms of R and R being at least 3, but when the sum of m and n is 9, R and R each contain not more than 9 carbon atoms.

8. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and, based on said oil, about 2% to about 15% by weightof a chlorinated aliphatic material having from 5 to about 24 carbon atoms selected from the group consisting of chlorinated aliphatic hydrocarbons wherein the amount of chlorine is from about 30% to about 70% of the theoretical and the product obtained by chemically substituting a part only of the chlorine in'a chlorinated aliphatic hydrocarbon with an alkyl thiocarbonate group, about 1% to about an S-amine 0,0-dialiphatic phosphorothioate of the structure,

where R is selected from the group consisting of -CH CH sulfurized -CH=CH and and R and R are each aliphatic radicals containing from 3 to 6 carbon atoms.

9. A lubricating composition comprising a major proportion of a hydrocarbon oil and (a) a chlorinated aliphatic material having from 5 to about 24 carbon atoms selected from the group consisting of chlorinated aliphatic hydrocarbons wherein the amount of chlorine is from about 30% to about 70% of the theoretical and the product obtained by chemically substituting a part only of the chlorine in a chlorinated aliphatic hydrocarbon with an alkyl thiocarbonate group, (b) a metal salt of a thio acid of phosphorus represented by the structure,

where R and R are selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals, M is a metal selected from the group consisting of Zn, Ba, Mg and Ca, n is the valence of M, and x is an integer from to' 1 (c) a phosphorized-sulfurized dicyclic terpene, the weight ratio of (a) to (b) being from about 1 to 15:1, the weight ratio of (b) to (0) being from about 4 to 6.511, the total weight percent of (a), (b) and (0), based on said oil, being about 4% to 15%, and (d) about 0.1% to about 1% by Weight, based on said oil, of an S-amine 0,0-dialiphatic phosphorothioate of the structure,

wherein m is an integer from 0 to 17, n is an integer from 0 to 17, the sum of m and n being from 9 to 17; R is selected from thegroup consisting of -CH CH sulfurized -CH=CH- and -CH=CH; R and R are selected from the group consisting of hydrogen and aliphatic radicals containing from 1 to 4 carbon atoms; X is selected from the group consisting of oxygen and sulfur; and R and R are each aliphatic radicals containing from 1 to 12 carbon'atoms, the sum of the carbon atoms of R and R being at least 3, but when the sum of m and n is 9, R and R each contain not more than 9'carbon atoms.

10. A lubricating composition comprising a major proportion of a hydrocarbon oil and (a) a chlorinated aliphatic material having from 5 to about 24 carbon atoms selected from the group consisting of chlorinated aliphatic hydrocarbons wherein the amount of chlorine is from about 30% to about 70% of the theoretical and the product obtained by chemically substituting a part only of the chlorine in a chlorinated aliphatic hydrocarbon with an alkyl thiocarbonate group, (b) a metal salt of a thio acid of phosphorus represented by the struc- Where R and R are selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals, M is a metal selected from the group consisting of Zn, Ba, Mg and Ca, 11 is the valence of M, and x is an integer from 0 to 1, (c) a phosphoriZed-sulfurized dicyclic terpene, the weight ratio of (a) to (b) being from about 1 to 15:1, the Weight ratio of (b) to (0) being from about 4 to :1, the total weight percent of (a), (b) and (c), based on said oil, being about 4% to 15%, and (d) about 0.1% to about 1% by weight, based on said oil, of an S-amine 0,0-dialiphatic phosphorothioate of the structure,

where m is an integer from 0 to 17, n is an integer from 0 to 17, the sum of m and n being from 9 to 17; R is selected from the group consisting of CH CH sulfurized CH=CH and CH=CH; R and R are selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms; and R and R are each aliphatic radicals containing from 1 to 12 carbon atoms, the sum of the carbon atoms of R and R being at least 3, but when the sum of m and n is 9, R and R each'con'tain not more than 9 carbon atoms.

11. A lubricating composition comprising a major proportion of a hydrocarbon oil and (a) a chlorinated aliphatic material having from 5 to about 24 carbon atoms selected from the group consisting of chlorinated aliphatic hydrocarbons wherein the amount of chlorine is from about 30% to about of the theoretical and the product obtained by chemically substituting a part only of the chlorine in a chlorinated aliphatic hydrocarbon with an alkyl thiocarbonate group, (b) a metal salt of a thio acid of phosphorus represented by the strucwhere R and R are selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals, M is a metal selected from the group consisting of Zn, Ba, Mg and Ca, 11 is the valence of M, and x is an integer from 0 to 1, (c) a phosphorized-sulfurized dicyclic terpene, the weight ratio of (a) to (b) being from about 1 to 1.521, the weight ratio of (b) to (0) being from about 4 to 65:1, the total weight percent of (a), (b) and (0), based on said oil, being about 4% to 15%, and (d) about 0.1% to about 1% by weight, based on said oil, of an S-amine 0,0-dialiphatic phosphorothioate of the structure,

(b) is a zinc salt of a dithio acid of phosphorous represented by the structure,

R10 /S y R20 S 2 wherein R and R are selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals.

13. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and (a) the product obtained by chemically substituting a part only Rao \S 2 wherein R and R are selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals, (c) a phosphorized-sulfurized dicyclic terpene obtained by reacting said terpene with a phosphorus sulfide at 100-l60 C., the weight ratio of (b) to being from about 4 to 6.5 :1, the weight ratio of (a) to (b) being from about 1' to 1.5:1, the total weight percent of (a), (b) and (0), based on said oil, being about 8% to 15%, and (d) about 0.1% to 1% by Weight, based on said oil, of an S-amine 0,0-dialiphatic phosphorothioate of the structure,

where m is an integer from 0 to 17, n is an integer from 0 to 17, the sum of m and n being from 9 to 17; R is selected from the group consisting 0f CH -CH sulfurized CH=CH and CH=CH-; R and R are selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms; and R and R are each aliphatic radicals containing from 1 to 12 carbon atoms, the sum of the carbon atoms of R and R being at least 3, but when the sum of m and n is 9, R and R each contain not more than 9 carbon atoms.

14. A lubricating composition comprising a major pro portion of a hydrocarbon lubricating oil and (a) the product obtained by chemically substituting a part only of the chlorine in a chlorinated aliphatic hydrocarbon having from 5 to 15 carbon atoms with an alkyl thiocarbonate group, (b) a zinc salt of a dithio acid of phosphorus represented by the structure,

wherein R and R are selected from the group consisting of acyclic alicyclic, and aromatic hydrocarbon radicals, (c) a phosphorized-sulfun'zed dicyclic terpene obtained by reacting said terpene with a phosphorus sulfide at 100- 160 C., the weight ratio of (b) to (0) being from about 4 to 65:1, the weight ratio of (a) to (b) being from about 1 to 1.511, the total weight percent of (a), (b) and (c), based on said oil, being about 8% to 15%., and (d) about 0.1% to 1% by weight, based on said oil, of an S- amine 0,0-dialiphatic phosphorothioate of the structure,

where R is selected from the group consisting of -CH -CH sulfurized CH=CH-- and and R and R are each aliphatic radicals containing from 3 to 6 carbon atoms.

15. A lubricating composition comprising a major proportion of a hydrocarbon lubricating oil and (a) a chlorinated petroleum naphtha-alkyl Xanthate group reaction product wherein said product contains about 25% 18 to about 40% by weight chlorine, (b) a zinc salt of a dithio acid of phosphorus represented by the structure,

wherein R and R are alkyl radicals, (c) a phosphorizedsulfurized dicyclic pinene obtained by reacting said pinene with a phosphorus sulfide at -160 C., the weight ratio of (b) to (0) being from about 4 to 65:1, the weight ratio of (a) to (b) being from about 1 to 15:1, the total Weight percent of (a), (b) and (0), based on said oil, being about 8% to 15%, and (d) about 0.1% to 1% by weight, based on said oil, of an S-amine 0,0-dialiphatic phosphorothioate of the structure,

where m is an integer from 0 to 17, n is an integer from 0 to.17, the sum of m and n being from 9 to '17; R is selected from the group consisting of CH -CH sulfurized CH=CH and CH=CH; R and R are selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms; and

- R and R are each aliphatic radicals containing from 1 where R is selected from V the group consisting of CH -CH sulfurized -CH=CH and V CH=CH- and R and R are each aliphatic radicals containing from 1 to 12 carbon atoms, the sum of the carbon atoms of R and R being at least 3.

18. A lubricating composition of claim 16 wherein the S-amine 0,0-di-aliphatic phosphorothioate is .a compound of the structure,

where R is selected from the group consisting of -CH -CH sulfurized C-H=CH and and R and R are each aliphatic radicals containing from 3 to 6 carbon atoms.

19. A lubricating composition of claim 16 wherein the S-amine 0,0-dialiphatic phosphorothioate is S-octadecenylamine 0,0-diis0propyl phosphorodithioate.

20. A lubricating composition of claim 16 wherein the S-amine 0,0-dialiphatic phosphorothioate is S-octadecenylamine 0,0-di-1,3-dimethylbutyl phosphorodithioate.

References Cited in the file of this patent UNITED STATES PATENTS 2,447,288 Smith et .al Aug. 17, 1948 2,798,045 Buck et al. July 2, 1957 2,809,934 Alford et a1 Oct. 15, 1957 2,850,452 Sands et al. Sept. 2, 1958 

1. A LUBRICATING COMPOSITION COMPRISING A MAJOR PROPORTION OF A HYDROCARBON LUBRICATING OIL AND, IN AN AMOUNT SUFFICIENT TO IMPROVE THE ANTIWEAR AND EXTREME PRESSURE PROPERTIES OF SAID OIL BUT NOT OVER ABOUT 10% BY WEIGHT, AN S-AMINE O,O-DIALIPHATIC PHOSPOROTHIOATE HAVING THE STRUCTURE, 